Create 4th-presentation-query.sql

Author: decarv

4th-presentation-query.sql

@@ -0,0 +1,34 @@
+/* ---------- Query 4 - Film rental distribution by category ---------- */
+
+WITH t1 AS (SELECT c.customer_id, 
+                   p.amount, 
+                   DATE_TRUNC('month', p.payment_date) AS payment_date,
+			         p.rental_id
+              FROM customer AS c
+                   JOIN payment AS p
+                    ON c.customer_id = p.customer_id),
+
+     t2 AS (SELECT t1.customer_id, 
+		   t1.payment_date,
+                   SUM(t1.amount) AS total_amtpaid,
+                   LEAD(SUM(t1.amount)) OVER(w) AS lead_num,
+                   LEAD(SUM(t1.amount)) OVER(w) - SUM(t1.amount) AS lead_dif,
+                   CASE 
+                       WHEN LEAD(SUM(t1.amount)) OVER(w) - SUM(t1.amount) < 0 THEN 0
+                       WHEN LEAD(SUM(t1.amount)) OVER(w) - SUM(t1.amount) >= 0 THEN 1
+                   END AS progress
+              FROM t1
+                   JOIN rental AS r
+                    ON r.rental_id = t1.rental_id
+                    AND t1.customer_id = r.customer_id
+             GROUP BY 1, 2
+            WINDOW w AS (PARTITION BY t1.customer_id ORDER BY DATE_TRUNC('month', t1.payment_date)))
+										  
+SELECT t2.payment_date,
+       COUNT(*) AS total_count,
+       SUM(t2.progress) AS progress_bymon,
+       COUNT(*) - SUM(t2.progress) AS regress_bymon
+  FROM t2
+ WHERE t2.progress IS NOT NULL
+ GROUP BY 1
+ ORDER BY 1;